1. Field of the Invention
The present invention relates to a sweeping apparatus, and more particularly, but not by way of limitation, to a motorized, towable sweeping apparatus for collecting dirt and debris over a surface to be swept.
2. History of Related Art
Advancements in the art of street sweeping apparatus are characterized and embodied in patents spanning more than a century. Original mechanized models were non-motorized versions, necessitated by the early state of the art. Incumbent upon the inventors of the 1800's was a street sweeping machine utilizing “horse power” in its strictest sense. Such machines utilized rotation of ground-surface-engaging wheels to drive sweeping brushes in a sweeping operation. Such a sweeper is disclosed in U.S. Pat. No. 35,365, issued to Daboll in 1862, wherein a cylindrically-shaped brush was operated through engagement of rigid frictional drive rollers for collection of dirt and debris in bin storage areas formed within a sweeping-unit housing.
Advancements in the sweeping art were consistent with those of a mechanized society. Chain drives, gears, and pawl-and-ratchet combinations were introduced in an effort to achieve a sweeping unit design which could be built, maintained, and operated economically with great effectiveness. With the advent of the internal combustion engine, such units became self-powered and therefore relatively complex and costly. But as complexity increased, so did problems in operation and maintenance. Debris and unwanted materials, although the collection of which was typically an object of the sweeping operations, often formed abrasives that interfered with a myriad of moving parts in the self-powered sweeping units.
The self-powered sweeping units proved to be most effective in large-scale sweeping operations. However, due to the overall size of such units, they were often impractical for smaller industrial uses in which several cleaning locations were spread apart. Physically and economically it proved to be impractical to transport large, self-powered sweepers for relatively small cleaning jobs.
As more recent patents illustrate, sweeper attachments have therefore been provided for lift trucks and similar motorized vehicles particularly adapted for pushing or pulling of the sweeper attachment over a surface to be swept. Such vehicles are often located at industrial sites for other unrelated uses.
Some of the advancements in attachable sweepers utilized the developments of the early art in direct wheel-to-brush-drive rotational interengagement. For example, U.S. Pat. No. 3,354,489, issued to S. V. Ehrlich on Nov. 28, 1967, discloses a sweeper attachment for a lift truck. This and other similar sweeping machines incorporate drive-wheel transmissions, one-way over-riding clutches, enclosed bin areas adjacent the brush, and means for engaging the unit for lifting it to deposit debris within. These units further include features such as floating steering and a method of attachment utilizing adaptation of all makes and models of lift trucks.
Another advancement in the area of attachable sweepers is that shown in U.S. Pat. No. 4,001,908, in which David W. Franklin is the inventor. In this 1977 patent, there is set forth and shown a sweeping apparatus for coupling to a motorized vehicle with design aspects adapted for increasing the efficiency of the sweeping operation as the sweeper passes over a surface to be swept. As shown therein, a sweeping brush is rotatably driven by a surface engaging wheel through one or more expandable drive capstans coaxially affixed to the sweeping brush. In recent years, the aspect of a towable sweeper with an independent, motorized sweeping brush has been developed and utilized. Today, towable sweeping units with motorized sweeping brushes permit enhanced sweeping of surface areas containing dirt and debris utilizing conventional vehicles such as pickup trucks and the like. Other improvements in the design and efficiency of such motorized, towable sweepers would, of course, be beneficial to sweeping operations.